This invention relates generally to heat sinks for electronic devices, and more specifically, to mounting and retention systems for heat sinks.
The use of heat sinks on electronic components is well known. Typically, a heat sink is arranged in close contact with a heat generating electronic component, such as a Central Processing Unit (CPU). As the power density of such components increases, heat transfer from the heat generating component to the surrounding environment becomes more and more critical to the proper operation of the component. Heat generated by the component is transferred to the heat sink and then dissipated from the heat sink to the surrounding air. One type of heat sink includes a metallic core in the form of a base plate. Heat dissipating fins extend from the base plate to increase the surface area of the heat sink. Heat transferred from the component to the base plate is spread throughout the base plate and to the fins fixed to the base plate. To further facilitate the dissipation of heat from the electronic component, a fan can be used to circulate air about outer surfaces of the fins and the base of the heat sink.
In the case of a CPU, known circuit board designs typically provide for the heat sink to be mounted directly on top of the CPU in a retention module that is in turn mounted on the circuit board. The heat sink is nested within the retention module, and a spring clip or other fastening mechanism and hardware is used to retain the heat sink to the retention module and apply a normal force to the heat sink to maintain physical contact between the heat sink and the CPU to ensure thermal flow of heat from the CPU to the heat sink.
In the past, certain processors have been specified for use with a particular retention module, and the retention module was commonly provided with the circuit boards for easy mounting of CPU's and heat sink assemblies. Consequently, heat sink assemblies and mounting hardware was designed for use with the retention modules. One example of such a retention module pertains to the widely used Intel Pentium 4 processors.
Next generation processors, such as the Intel Prescott T processor, requires a different layout in the circuit board than the Pentium 4 processors, thereby rendering known retention modules and heat sink assemblies incompatible with the new processors. Developing new heat sinks and hardware assemblies for mounting of the heat sinks on the new processors and circuit board layouts is a difficult and expensive proposition. Additionally, meeting the increased heat transfer needs of more powerful processors adds to the challenge of cooling new processor technology.